Tab for tear strip of container wall

ABSTRACT

This disclosure describes a tab of sheet material for attachment to an easy-opening container wall. The tab may include a weakened zone positioned to allow limited flexing of the tab to permit raising of the handle end of the tab sufficiently to get the finger between the handle end of the tab and the container wall. The weakened zone is configured and oriented so that the tab has substantial resistance to tearing between the weakened zone and the nose end thereof during use of the tab. The tab has a bead at the nose end thereof which is deformed into a relatively pointed rupturing nose for applying a concentrated force to the container wall.

United States Patet 1111 3,503,075

[ Erma 3,338,463 8/1967 Henrickson 1. 220/54 355 SYMP R084 45429 3,411,662 1 1/1968 SilVEfl 1. 220 54 p 790-029 3446,3119 5/1969 Brown. 220/48 [22] Filed Jan. 9,1969 [45] Patented Ju|y 9 1 7 Primary ExammerGeorge T. Hall Attorney-Smyth, Roston and Pavitt ABSTRACT: This disclosure describes a tab of sheet material [54] CONTAINER WALL for attachment to an easy-opening container wall. The tab may include a weakened zone positioned to allow limited flex- 2 4 ing of the tab to permit raising of the handle end of the tab suf [51] Int. Cl 1 v 1 1 lBfiSd 17/24 ficiently to get the finger between the handle end of the tab [50] Field Of Search 220/48, 54, and the container walL The weakened zone is configured and 53 oriented so that the tab has substantial resistance to tearing between the weakened zone and the nose end thereof during [56] References (Med use of the tab. The tab has a bead at the nose end thereof UNITED STATES PATENTS which is deformed into a relatively pointed rupturing nose for 3,501,046 3/1970 Jasper et al. 220/54 applying a concentrated force to the container wall.

PATENTED JUL20I97| 3.593875 sum 1 or 2 TAB F( )R TEAR STRIP 01F CONTAHNER WALL BACKGROUND OF THE INVENTION The present invention relates to a tab of the type usable with an easy-opening container. in one type of easy-opening container one wall of the container has a line of weakness therein defining a relatively large removable panel. A tab is mounted on the panel with a rivet so that the nose or forward end of the tab lies adjacent the line of weakness. In use of the tab, the tab is first lifted or pivoted to rupture a predetermined length of the wall along the line of weakness and then pulled outwardly to continue the rupturing along the line of weakness to remove the panel from the container wall.

One tab often used in this environment has a U-shaped slit which extends a major distance around the rivet receiving aperture of the tab. The ends of the slit terminate forwardly, i.e. on the nose end side of the rivet. A bend line extends transversely of the tab between the ends of the slit on the forward side of the rivet.

This easy-opening container wall construction, although ostensibly quite simple is fraught with numerous interrelated and difficult problems. First, as the forces applied to the tab, particularly when the panel is relatively large, are substantial, the tab is subject to structural failure during use. A common form of failure is tearing of the sheet material of the tab from the end of the slit toward the nose end thereby disabling the tab from performing its intended function.

The tearing of the sheet material is caused, at least in substantial part, by the slit in the tab in that the sheet material of the tab adjacent the slit is placed in tension during operation of the tab. The slit is necessary or desirable for many easyopening container constructions to prevent the tab from becoming extremely longitudinally rigid to the extent that it is very difficult to raise the handle end of the tab sufficiently to get a finger thereunder.

Another problem with the slit tab described above results from the fact that it bends the container wall inwardly about a line lying forwardly of the rivet. This means that the length of the arc of rupture in response to pivoting of the handle end of the tab is relatively small. With only a small arc ruptured, it is often difficult to continue the rupturing operation by exerting an outward pulling force on the tab. This is particularly true for large panels.

To break out longer arcs of the line of weakness, the user may pivot the tab through 90 or more from its initial position and then pivot the tab in the reverse direction until it forms about a 3045 angle with the container wall. The outward pulling force is then exerted on the tab. This form of operation of the tab may slightly increase the length of arc of rupture but results in bending of the container wall segment or panel a substantial distance into the container. ln addition, the bending of the sheet metal tab through 90 in one direction and then through perhaps 60 in the other direction substantially weakens the sheet material so that the tab may fracture during the outward pulling phase of the removal operation.

To facilitate opening of an easy-opening container, it is important that the rupturing end or nose end of the tab properly concentrate the force on the container wall. As it is desirable to provide a reinforcing bead around the nose end of the tab to improve the strength of the tab, there is a problem of how to maintain this strengthening bead and still provide for the necessary concentration of rupturing forces on the container wall.

SUMMARY OF THE INVENTION The present invention provides a tab which ofiers high resistance to the tear out failure described above and which possesses sufficient flexibility to permit lifting of the handle end of the tab with relative ease a distance sufficient to permit the user to get his finger therebelow. The present invention teaches that these desirable results can be accomplished by weakening the tab in a preselected zone to provide the necessary flexibility.

These concepts of the invention can be advantageously embodied in a tab of sheet material which includes a handle end, a nose end, a finger receiving opening adjacent the handle end, and a location or attachment zone between the finger receiving opening and the nose end for cooperating with attaching means to connect the tab to a container wall. According to a preferred practice of the present invention, the weakening of the tab takes the form of an opening or cut in the tab. The opening or cut may be, for example, one or more linelike slits, one or more slots, or virtually any break or fracture in the sheet metal which provides the necessary weakening effect. The words "cut" and opening" are used generically herein to mean any such break in the sheet material which produces the desired weakening effect. The opening can be formed in any suitable manner and no method limitation is intended by use of the word cut.

With the tab weakened, it flexes when the user applies a lifting force to the handle end of the tab. The tab flexes sufficiently to permit lifting of the handle end of the tab an amount sufficient to permit the user to get his finger between the handle end of the tab and the can end. The tab is provided with stiffening means which provides sufficient rigidity in the tab to prevent bending failure thereof during use of the tab.

The weakened zone should be located so that the paddle section of the can end bends inwardly about a hinge line lying rearwardly of the center of the attachment zone of the can end. Preferably the bend lines lies rearwardly of the attachment zone. With this construction a longer arc of initial rupture along the score line is obtained in response to minimum pivotal movement of the tab. In addition, the sheet material of the tab is not subject to tearing or other structural failure experienced with prior art tabs.

Preferably the weakened zone or opening should be intermediate the finger receiving opening and a transverse line drawn through the center of the attachment zone of the tab, i.e. the weakened zone should extend no more than about degrees around the attachment zone. In a preferred embodiment of the invention, the weakened zone lies rearwardly of the attaching means.

To provide optimum flexing characteristics, the opening should have a portion which extends generally transverse to the longitudinal axis of the tab. To provide additional flex in a tab having a bathtub section, the ends of the weakened zone may terminate in the sidewall of the bathtub section.

To resist tear out, the ends of the opening may terminate in small apertures or the ends of the opening may be appropriately curved. In a preferred form of the invention the weakened zone is curved throughout so that it cannot assist tearing by following the straight grain structure of the metal.

The present invention also provides for venting of the container prior to removing of the removable panel. This is accomplished by use of fracturable attachment means for weakly joining the can end to the tab on the rearward side of the weakened zone. The flexing action in the tab provides some delay between the rupturing of the fracturable means and the rupture of the score line. This delay although typically only for a fraction of a second is sufficient to cause substantial pressure equalization through the vent opening prior to rupturing of the score line.

Another feature of the present invention resides in the formation of a very strong and efficient rupturing portion at the nose end of the tab. To reinforce the tab it is desirable to turn the marginal portions of the tab inwardly to form a reinforcing bead. For maximum strength, this bead should extend at least substantially continuously around the nose end of the tab. At the nose end of the tab and preferably on the longitudinal axis of the tab, this bead is deformed into a relatively sharp, pointed, double layer rupturing nose which is adapted to forcibly engage the container wall adjacent the line of weakness and apply a concentrated force thereto. This rupturing nose has the advantage of being very strong in that it is constructed of two layers of sheet material. lt is also easy to make in that it can be formed with one hit from an appropriate set of tools. In addition, a rupturing nose of this construction allows the reinforcing bead to extend continuously around the nose end of the tab to thereby provide a tab of maximum strength.

The invention, both as to its organization and method of operation together with further features and advantages thereof may best be understood by reference to the following description taken in connection with the accompanying illustrative drawing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of a tab constructed in accordance with the teachings of this invention mounted on an easy-opening container wall.

FIG. 2 is an enlarged fragmentary sectional view taken along line 2-2 of FIG. 1.

FIG. 3 is an enlarged top plan view of the tab.

FIG. 4 is an enlarge (1 bottom view of the tab.

FIG. 5 is an enlarged plan view illustrating a second form of weakened zone of the tab.

FIG. 6 is an enlarged plan view illustrating a third form of weakened zone for the tab.

FIG. 7 is an enlarged plan view illustrating a fourth form of weakened zone for the tab.

FIGS. 8-10 are fragmentary sectional views similar to FIG. 2 illustrating the operation of the tab. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings and in particular to FIG. 1 thereof, reference numeral 11 designates an easy-opening container wall or can end constructed in accordance with the teachings of this invention. The easy-opening container wall 11 includes a can end 13 having a peripheral attachment flange 15 formed integrally therewith for attaching the can end to a container body 16 (FIG. 2). A line of weakness 17 in the form of a score line defines a removable panel 19. A tab 21 constructed in accordance with the teachings of this invention is attached to the panel 19 by any suitable means such as a hollow rivet 23 formed integrally with the panel 19.

The can end 13 is formed of sheet material such as sheet aluminum. The line of weakness 17 lies closely adjacent the attachment flange 15 and the panel 19 covers substantially all of the area in plan of the cam end 13, although the present invention is not restricted to any particular size or orientation of removable panel. Althoughthe can end 13 and the panel 19 are circular and concentric in the embodiment illustrated, these members may assume any suitable configuration.

With reference to FIGS. 2-4, the tab 21 is preferably integrally constructed from sheet material such as sheet aluminum. The tab has a handle or rearward end 25 and a nose or forward end 27. A marginal or peripheral portion of the sheet material of the tab 21 is turned inwardly to form an outer reinforcing bead 29'which preferably extends continuously and completely around the tab. The tab 21 has a finger receiving opening 31 sized to receive the finger of a user therein. A region of the sheet material surrounding the opening 31 is curled outwardly to provide an inner reinforcing bead 33. The inner reinforcing bead 33 provides a smooth inner surface for engagement by the finger of a user.

At the nose end 27 of the tab 21, the bead 29 has been deformed as shown in FIGS. 24 to define a relatively pointed double layer rupturing nose 35. As best seen in FIG. 2, the rupturing nose 35 has an outer layer 37 and an inner layer 39 which provide the rupturing nose 35 with substantial strength. The rupturing nose 35 is preferably formed by striking a portion of the bead 29 located centrally of the nose end 27 with suitable tooling to form an upwardly opening indentation 41. As shown in FIG. 2, the rupturing nose 35 projects downwardly and terminates a short distance beneath the adjacent portions of the outer reinforcing bead 29. Thus, the rupturing nose 35 is in a position to contact the panel 19 and apply a concentrated rupturing force thereto.

The tab 21 has a circular rivet receiving aperture 43 adjacent the nose end 27 of the tab and a second smaller aperture 45 forwardly thereof. The centers of the apertures 43 and 45 and the rupturing nose 35 are all preferably located on the longitudinal axis of the tab 21. In the embodiment shown in FIGS. 2--4, the tab 21 has a bottom wall 47 which, as shown in FIG. 2, is at a lower elevation than a surrounding wall portion 49. A sloping connecting or sidewall 51 integrally joins the wall portion 49 to the bottom wall 47. The apertures 43 and 45 are located in this bottom wall 47 The sidewall 51 may.

be supported by the bead 29 if desired.

In the embodiment shown in FIGS. 24, the tab 21 has a weakened zone in the form of a slit 53 which extends only a small distance around the aperture 43. The slit 53 is formed in the bottom wall 47 and extends completely therethrough. As shown in FIGS. 3 and 4, the slit 43 has an arcuate portion 55 which is generally concentric with the aperture 43 and curved end portions 57 which curve away from the nose end of the tab 27 to provide further resistance to tear out.

The slit 53 lies closely adjacent the aperture 43 and no por' tion thereof extends on the nose end side of a transversely extending line A-A drawn through the rearwardmost point of the aperture 43. Thus, tab flexibility and substantial resistance to tear out failure are provided.

The tab 21 is mounted on the can end 13 as shown in FIGS. 1 and 2. Thus, the rivet 23 projects through the aperture 43 to attach the tab 21 to panel 19. A fracturable rivet 59 projects through the aperture 45. The fracturable rivet 59 is of the type which will easily rupture in response to an upward lifting force on the tab 21 to thereby provide a vent opening in the panel 19. With the tab 21 thus attached to the panel 19, the rupturing nose 35 overlies a narrow region of the line of weakness l7 and the tab 21 projects radially inwardly from the periphery of the panel 19 and lies completely within the line of weakness 17. The fracturable rivet 59 also maintains alignment of the tab 21 to assure that the rupturing nose 35 remains precisely positioned over the score line 17.

Alternate forms of weakened zones are shown in FIGS. 5- 7 wherein portions identical to portions of FIGS. 1-4 are designated by corresponding reference numbers followed by the letters a c, respectively. In FIG. 5, the weakened zone takes the form of an arcuate slit 61 which is formed in the bottom wall 470 of a tab which is otherwise identical to the tab 21 shown in FIGS. 14. The slot 61 terminates at each end in a small diameter aperture 63 also formed in the bottom wall 47a. In the embodiment shown in FIG. 5, the slit 61 is oriented in the same manner as the slit 53 and thus, it lies closely adjacent an aperture 43' for receiving a strong attaching rivet with the curve of a slit 61 opening toward the handle end 25 of the tab.

In FIG. 6, the weakened zone takes the form of an arcuate slot 65 having an arcuate central portion 67 and relatively straight end portion 69. The slot 65 is formed in the bottom wall 47b of a tab which is otherwise identical to the tab 21. The slot 65 is oriented in the same manner as the slit 53 and thus, it lies closely adjacent a rivet receiving aperture 43b.

FIGS. 7 shows a tab 21c including a bottom wall 470, connecting wall 510, wall portion 490, apertures 43c adjacent the nose end of the tab, aperture 450, and a weakened zone in the form of an arcuate slot 70. The slot 70 extends across the bottom wall 47c and slightly into the side wall 510 to provide added flexibility for the tab. In the embodiment illustrated the slot 70 extends just through the radius portion which blends the bottom wall 470 into the side wall 510 and terminates at a line 72 which marks the end of such radius portion.

REgardless of the particular form of the weakened zone, the operation of the tab 21 can be illustrated with reference to FIGS. 8- 10. FIG. 8 illustrates the tab 21 after the handle end 25 thereof has been raised slightly. The initial upward movement of the handle end 25 of the tab 21 ruptures the fracturable rivet 59 to form a vent opening 71 in the panel 19. The tab 21 overlies the vent opening and acts as a baffle should the passage of gas through the vent opening 71 result in some of the product within the container 16 flowing outwardly through the vent opening.

With the fracturable rivet 59 fractured, the handle end 2d can be moved upwardly a greater amount to cause the rupturing nose 35 to apply a substantial force to the can end 113 along the score line 117. During all of the upward movement of the handle end of the tab 211, the slit 53 allows such movement to occur with relative ease to enable the user to get his finger between the handle end 25 and the panel lit. The slit makes the tab flexible so that it can be raised or pivoted a greater amount before the score line E17 ruptures than if no shit were provided. As it takes time to raise the tab this additional amount, the tab provides a time delay between rupture of rivet 59 and of score line 117. This delay is sufficient to allow complete pressure equalization through vent opening 111 prior to the rupture of the score line ll? so that no product disturbance results.

When the handle end 25 of the tab 21 is raised to approximately the position shown in H6. 9, the rupturing nose 315i fractures the score line 17 to form an opening 731 in the can end 13. Because of the location of the slit 53, the panel I19 bends just rearwardly of the rivet 23 as shown in MG. 9. This causes a relatively long length of the can end 1133 along the score line 117 to be brolten in response to pivotal movement of the tab 21 and without the necessity of pivoting the tab to a relatively steep angle with reference to the panel 119.

The final phase of the opening operation is shown in FIG. 10. In P16. 110, the user is directing an outward pulling force on the tab 21 to tear the panel 19 from the can end i3. Such outward pulling is accomplished relatively easily because of the long initial length of the score line 117 which was broken in response to the first phase of tab operation, ie the pivoting of tab 21.

Although exemplary embodiments of the invention have been shown and described, many changes modifications and substitutions may be made by one having ordinary skill in the art without necessarily departing from the spirit and scope of this invention.

I claim:

1. A tab of the type attachable to an easy opening container wall comprising:

a nose end and a lifting end, said tab being integrally constructed of sheet material and including means for stiffening said tab against bending;

said tab having a finger receiving opening adjacent the lifting end thereof and a relatively smooth surface at least partially surrounding the finger receiving opening;

said tab having a preselected region intermediate said nose end and said opening for cooperating with attaching means for attaching the tab to the container wall;

the sheet material adjacent said preselected region being severed along a path to provide the tab with a flexing characteristic which facilitates moving of the lifting end of the tab away from the container wall in response to a minimum lifting force;-and

said path being configured and located to produce no bend line in the tab as a result of normal use the tab.

2. A tab as defined in claim 1 wherein a region of the sheet material between said nose end and said finger receiving opening is depressed beneath the surrounding region of the sheet material to define a bottom well, said bottom wall being joined to said surrounding region of sheet material by a connecting wall, said preselected region and said path being located in said bottom wall.

3. A tab as defined in claim 2 wherein said path extends across said bottom wall and terminates in said connecting wall.

4. A tab as defined in claim 11 wherein the center of said preselected region lies closely adjacent the longitudinal axis of the tab, said path does not extend a significant distance on the nose end side of a line drawn transverse to the longitudinal axis of the tab and through the edge of said preselected region nearest the handle end of the tab.

5. A tab of the type for attachment to an easy-opening con tainer wall, said tab being integrally constructed of sheet material and including:

a nose and and a lifting end, marginal portions of said tab being turned to form generally longitudinally extending reinforcing bead portions on the opposite sides of the tab to strengthen the tab longitudinally;

said tab having finger receiving opening adjacent the lifting end thereof with the sheet material adjacent said opening being turned to define an inner reinforcing bead extending at least partially around said opening;

an aperture in the region of sheet material between the nose end and said finger receiving opening for receiving attaching means for attaching the tab to the container wall;

the sheet material between the center of said aperture and said finger receiving opening being out along a path to provide the tab with a flexing characteristic which facilitates raising of the handle end of the tab above the container wall in response to a minimum lifting force;

said path extending no more than about around said aperture and being configured and located to produce no bend line in the tab forward of the aperture as a result of normal use of the tab whereby the tab has substantial resistance to tearing between said path and said nose end; and

said path having a portion extending generally transverse to the longitudinal axis of said tab.

6. A tab as defined in claim 5 wherein said cut includes a slit.

7. A tab as defined in claim 5 wherein said cut includes a slot.

8. A tab of the type attachable to an easy-opening container wall comprising:

a tab body and an attachment portion both constructed of sheet material, the tab body circumscribing the attachment portion;

said tab body having a lifting end and a nose end, a marginal portion of the sheet material of said tab body being turned inwardly to define a stiffening bead which extends at least substantially continuously along the opposite sides of the tab body and at least substantially continuously along the nose end of the tab body;

said attachment portion being integrally joined to the tab body and adapted for attaching the tab to the easy-opening container wall; and

the portion of said bead at the central location along the nose end of said tab body being formed into a relatively pointed double layer rupturing nose adapted to face the easy-opening container wall and apply a relatively concentrated rupturing force thereto.

9. A tab as defined in claim tit wherein said bead has an indentation therein above said rupturing nose, said indentation opening upwardly, said rupturing nose terminating beneath the adjacent portions of said bead.

it). A tab of the type for attachment to an easy-opening con tainer wall, said tab being integrally constructed of sheet material and including;

a nose end and a lifting end, marginal portions of said tab being turned to form generally longitudinally extending reinforcing bead portions on the opposite sides of the tab to strengthen the tab longitudinally;

said tab having a finger receiving opening adjacent the lifting end thereof with the sheet material adjacent said opening being turned to define an inner reinforcing bead extending at least partially around said opening;

an aperture in the region of sheet material between the nose end and said finger receiving opening for receiving attaching means for attaching the tab to the container wall;

the sheet material between the center of said aperture and said finger receiving opening being out along a path to provide the tab with a flexing characteristic which facilitates raising of the handle end of the tab above the container wall in response to a minimum lifting force;

said path extending no more than about 180 around said aperture and being located to prevent formation of a bend line in the tab forwardly of said aperture whereby the tab has substantial resistance to tearing between said path and said nose end;

said path having a portion extending generally transverse to the longitudinal axis of said tab; and

said bead portions extending at least substantially continuously along said nose end and forming a substantially continuous bead along said nose end, the portion of said bead located centrally of the nose end of said tab Ming formed into a relatively pointed double layer rupturing nose.

11. An easy-opening container wall comprising:

a container wall having a line of weakness therein defining a panel at least partially removable from the container wall;

a tab of sheet material having a nose end and a handle end at the forward and rear ends, respectively, of the tab;

means for attaching the tab at a location intermediate said handle end and said nose end to said panel with said nose end lying closely adjacent said line of weakness and with said tab overlying at least a portion of the panel whereby lifting of said handle end forces said nose end against said container wall to cause rupture of said line of weakness;

the sheet material of said tab adjacent said attaching means being weakened along a path to permit flexing of said tab in response to an outward lifting force on said handle end; and

said path being configured and positioned to cause a paddle section of the panel to bend inwardly about a bend line lying rearwardly of the center of said attaching means in response to lifting of said handle end.

12. An easy opening container wall as defined in claim 11 wherein said path includes a slot.

13. An easy opening container wall as defined in claim 11 including rupturable attaching means for attaching said tab to said container wall rearwardly of said path, said rupturable attaching means being rupturable from the container wall upon initial movement of the handle end of the tab away from the container wall to form a vent opening in the container wall.

14. A tab of the type attachable to a tear portion of an easyopening container wall to initiate severance of the tear portion through pivotal movement of the tab to cause depression of a section of the tear portion inwardly, said tab comprising:

a nose end and a lifting end at the forward and rear ends of the tab, respectively, said tab being constructed of sheet material and including integral means for stiffening the tab longitudinally;

said tab having a zone adjacent the nose end thereof adapted for attachment to the tear portion of the easy opening container wall; and

the sheet material of said tab adjacent said zone being severed along an elongated path to reduce the rigidity of the tab to bending forces to permit said tab to initiate severance of the tear portion by pivoting about a hinge line lying rearwardly of the center of said zone without forming a bend line in the tab.

15. A tab as defined in claim 14 wherein the tab has an integral bathtub section lying adjacent the nose end, said bathtub section having a bottom wall and connecting wall which integrally connects the bottom wall to the remainder of the tab, said path lying within said bathtub section.

16. A tab as defined in claim 14 wherein the tab has a finger receiving opening adjacent the lifting end thereof and said path lies between said finger receiving opening and said nose end, said path being completely surrounded by sheet material, said hinge line about which the tab is pivotable lying rearwardly of said zone.

17. An easy opening container wall as defined in claim 20 wherein said means for attaching includes an aperture in said taband a rivet projecting through said tab and said path does not extend significantly on the nose end side of a line drawn transverse to said tab through the rearwardmost point of said aperture.

18. A'tab of the type attachable to an easy opening container wall comprising:

a member of sheet material, said member having a nose end and a lifting end and being substantially rigid between said ends; said member having a preselected region intermediate said nose end and said lifting end adapted for attachment to the container wall;

the sheet material adjacent said preselected region being severed along a path to reduce the rigidity of aid member to thereby facilitate the movement of said lifting end of the member away from the container wall when said member is attached at said preselected region to said container wall; and

said path being configured and located to produce no bend line in said member as a result of moving the lifting end of the member away from the container wall to form an opening in the container wall.

19. A tab as defined in claim 18 wherein said path does not extend on the nose end side of said preselected region.

20. A tab of the type attachable to an easy opening container wall comprising:

a member of sheet material, said member having a nose end and a lifting end and being substantially rigid between said ends;

said member having a preselected region intermediate said nose end and said lifting end adapted for attachment to the container wall;

the sheet material adjacent said preselected region being severed along a path to reduce the rigidity of said member to thereby facilitate the movement of said lifting end of the member away from the container wall when said member is attached at said preselected region to said container wall; and

means for preventing the severance of the sheet material along said path from forming a hinge line in said member as a result of moving the lifting end of the member away from the container wall to form an opening in the container wall.

21. An easy-opening container wall comprising:

a container wall having a line of weakness therein defining a panel at least partially removable from the container wall;

a tab of sheet material having a nose end and a handle end at the forward and rear ends, respectively, of the tab;

means for attaching the tab at a location intermediate said handle end and said nose end to said panel with said nose end lying closely adjacent said line of weakness and with said tab overlying at least a portion of the panel whereby lifting of said handle end forces said nose end against said container wall to cause rupture of said line of weakness;

the sheet material of said tab adjacent said attaching means being weakened along a path to permit flexing of said tab in response to an outward lifting force on said handle end; and

said tab including means responsive to the movement of said handle end of said tab away from the container wall for being a section of the container wall inwardly about a bend line lying generally on the handle end side of the center of said attaching means.

22. An easy opening container wall as defined in claim 21 wherein said bend line lies on the handle end side of said attaching means. 

1. A tab of the type attachable to an easy-opening container wall comprising: a nose end and a lifting end, said tab being integrally constructed of sheet material and including means for stiffening said tab against bending; said tab having a finger receiving opening adjacent the lifting end thereof and a relatively smooth surface at least partially surrounding the finger receiving opening; said tab having a preselected region intermediate said nose end and said opening for cooperating with attaching means for attaching the tab to the container wall; the sheet material adjacent said preselected region being severed along a path to provide the tab with a flexing characteristic which facilitates moving of the lifting end of the tab away from the container wall in response to a minimum lifting force; and said path being configured and located to produce no bend line in the tab as a result of normal use the tab.
 2. A tab as defined in claim 1 wherein a region of the sheet material between said nose end and said finger receiving opening is depressed beneath the surrounding region of the sheet material to define a bottom wall, said bottom wall being joined to said surrounding region of sheet material by a connecting wall, said preselected region and said path being located in said bottom wall.
 3. A tab as defined in claim 2 wherein said path extends across said bottom wall and terminates in said connecting wall.
 4. A tab as defined in claim 1 wherein the center of said preselected region lies closely adjacent the longitudinal axis of the tab, said path does not extend a significant distance on the nose end side of a line drawn transverse to the longitudinal axis of the tab and through the edge of said preselected region nearest the handle end of the tab.
 5. A tab of the type for attachment to an easy-opening container wall, said tab being integrally constructed of sheet material and including: a nose end and a lifting end, marginal portions of said tab being turned to form generally longitudinally extending reinforcing bead portions on the opposite sides of the tab to strengthen the tab longitudinally; said tab having a finger receiving opening adjacent the lifting end thereof with the sheet material adjacent said opening being turned to define an inner reinforcing bead extending at least partially around said opening; an aperture in the region of sheet material between the nose end and said finger receiving opening for receiving attaching means for attaching the tab to the container wall; the sheet material between the center of said aperture and said finger receiving opening being cut along a path to provide the tab with a flexing characteristic which facilitates raising of the handle end of the tab above the container wall in response to a minimum lifting force; said path extending no more than about 180* around said aperture and being configured and located to produce no bend line in the tab forward of the aperture as a result of normal use of the tab whereby the tab has substantial resistance to tearing between said path and said nose end; and said path having a portion extending generally transverse to the longitudinal axis of said tab.
 6. A tab as defined in claim 5 wherein said cut includes a slit.
 7. A tab as defined in claim 5 wherein said cut includes a slot.
 8. A tab of the type attachable to an easy-opening container wall comprising: a tab body and an attachment portion both constructed of sheet material, the tab body circumscribing the attachment portion; said tab body having a lifting end and a nose end, a marginal portion of the sheet material of said tab body being turned inwardly to define a stiffening bead which extends at least substantially continuously along the opposite sides of the tab body and at least substantially continuously aloNg the nose end of the tab body; said attachment portion being integrally joined to the tab body and adapted for attaching the tab to the easy-opening container wall; and the portion of said bead at the central location along the nose end of said tab body being formed into a relatively pointed double layer rupturing nose adapted to face the easy-opening container wall and apply a relatively concentrated rupturing force thereto.
 9. A tab as defined in claim 8 wherein said bead has an indentation therein above said rupturing nose, said indentation opening upwardly, said rupturing nose terminating beneath the adjacent portions of said bead.
 10. A tab of the type for attachment to an easy-opening container wall, said tab being integrally constructed of sheet material and including; a nose end and a lifting end, marginal portions of said tab being turned to form generally longitudinally extending reinforcing bead portions on the opposite sides of the tab to strengthen the tab longitudinally; said tab having a finger receiving opening adjacent the lifting end thereof with the sheet material adjacent said opening being turned to define an inner reinforcing bead extending at least partially around said opening; an aperture in the region of sheet material between the nose end and said finger receiving opening for receiving attaching means for attaching the tab to the container wall; the sheet material between the center of said aperture and said finger receiving opening being cut along a path to provide the tab with a flexing characteristic which facilitates raising of the handle end of the tab above the container wall in response to a minimum lifting force; said path extending no more than about 180* around said aperture and being located to prevent formation of a bend line in the tab forwardly of said aperture whereby the tab has substantial resistance to tearing between said path and said nose end; said path having a portion extending generally transverse to the longitudinal axis of said tab; and said bead portions extending at least substantially continuously along said nose end and forming a substantially continuous bead along said nose end, the portion of said bead located centrally of the nose end of said tab being formed into a relatively pointed double layer rupturing nose.
 11. An easy-opening container wall comprising: a container wall having a line of weakness therein defining a panel at least partially removable from the container wall; a tab of sheet material having a nose end and a handle end at the forward and rear ends, respectively, of the tab; means for attaching the tab at a location intermediate said handle end and said nose end to said panel with said nose end lying closely adjacent said line of weakness and with said tab overlying at least a portion of the panel whereby lifting of said handle end forces said nose end against said container wall to cause rupture of said line of weakness; the sheet material of said tab adjacent said attaching means being weakened along a path to permit flexing of said tab in response to an outward lifting force on said handle end; and said path being configured and positioned to cause a paddle section of the panel to bend inwardly about a bend line lying rearwardly of the center of said attaching means in response to lifting of said handle end.
 12. An easy opening container wall as defined in claim 11 wherein said path includes a slot.
 13. An easy opening container wall as defined in claim 11 including rupturable attaching means for attaching said tab to said container wall rearwardly of said path, said rupturable attaching means being rupturable from the container wall upon initial movement of the handle end of the tab away from the container wall to form a vent opening in the container wall.
 14. A tab of the type attachable to a tear portion of an easy-opening container wall to initiate severance of the tear portion through pivotal movement of the tab to cause depression of a section of the tear portion inwardly, said tab comprising: a nose end and a lifting end at the forward and rear ends of the tab, respectively, said tab being constructed of sheet material and including integral means for stiffening the tab longitudinally; said tab having a zone adjacent the nose end thereof adapted for attachment to the tear portion of the easy opening container wall; and the sheet material of said tab adjacent said zone being severed along an elongated path to reduce the rigidity of the tab to bending forces to permit said tab to initiate severance of the tear portion by pivoting about a hinge line lying rearwardly of the center of said zone without forming a bend line in the tab.
 15. A tab as defined in claim 14 wherein the tab has an integral bathtub section lying adjacent the nose end, said bathtub section having a bottom wall and connecting wall which integrally connects the bottom wall to the remainder of the tab, said path lying within said bathtub section.
 16. A tab as defined in claim 14 wherein the tab has a finger receiving opening adjacent the lifting end thereof and said path lies between said finger receiving opening and said nose end, said path being completely surrounded by sheet material, said hinge line about which the tab is pivotable lying rearwardly of said zone.
 17. An easy opening container wall as defined in claim 20 wherein said means for attaching includes an aperture in said tab and a rivet projecting through said tab and said path does not extend significantly on the nose end side of a line drawn transverse to said tab through the rearwardmost point of said aperture.
 18. A tab of the type attachable to an easy opening container wall comprising: a member of sheet material, said member having a nose end and a lifting end and being substantially rigid between said ends; said member having a preselected region intermediate said nose end and said lifting end adapted for attachment to the container wall; the sheet material adjacent said preselected region being severed along a path to reduce the rigidity of aid member to thereby facilitate the movement of said lifting end of the member away from the container wall when said member is attached at said preselected region to said container wall; and said path being configured and located to produce no bend line in said member as a result of moving the lifting end of the member away from the container wall to form an opening in the container wall.
 19. A tab as defined in claim 18 wherein said path does not extend on the nose end side of said preselected region.
 20. A tab of the type attachable to an easy opening container wall comprising: a member of sheet material, said member having a nose end and a lifting end and being substantially rigid between said ends; said member having a preselected region intermediate said nose end and said lifting end adapted for attachment to the container wall; the sheet material adjacent said preselected region being severed along a path to reduce the rigidity of said member to thereby facilitate the movement of said lifting end of the member away from the container wall when said member is attached at said preselected region to said container wall; and means for preventing the severance of the sheet material along said path from forming a hinge line in said member as a result of moving the lifting end of the member away from the container wall to form an opening in the container wall.
 21. An easy-opening container wall comprising: a container wall having a line of weakness therein defining a panel at least partially removable from the container wall; a tab of sheet material having a nose end and a handle end at the forward and rear ends, respectively, of the tab; means for attaching the tab at a location intermediate said handle end and said nose end to said panel with said nose end lying closely adjacent said line of weakNess and with said tab overlying at least a portion of the panel whereby lifting of said handle end forces said nose end against said container wall to cause rupture of said line of weakness; the sheet material of said tab adjacent said attaching means being weakened along a path to permit flexing of said tab in response to an outward lifting force on said handle end; and said tab including means responsive to the movement of said handle end of said tab away from the container wall for being a section of the container wall inwardly about a bend line lying generally on the handle end side of the center of said attaching means.
 22. An easy opening container wall as defined in claim 21 wherein said bend line lies on the handle end side of said attaching means. 